TextField

Remarks

One editing core under every field in the set. A text box, a search box, a numeric input and a combo box's editable half are one caret, one selection and one keyboard map wearing four skins; writing the map four times is how a control library ends up with a field where Ctrl-Left works and one where it does not.

⚠ Single line unless AcceptsNewlines says otherwise, which only TextArea does. A one-line field's value scrolls sideways rather than wrapping; a text area wraps, takes a newline from Enter, and moves its caret between lines. Both are the same caret, the same selection and the same keyboard map — the difference is three predicates rather than a second control.

⚠ A text area does not scroll vertically yet. Its lines are drawn where they fall and a value taller than the box is clipped by it, which is honest and is not enough: the box is sized by the theme (textarea { min-height }) and a caller that expects to hold a long document should say how tall it wants to be. A scroll region round the text is owed.

The caret is an index into the value and the selection is a second one. Both are UTF-16 indices on grapheme boundaries, which is what ShapedText works in — so moving the caret over an emoji or a Devanagari syllable steps over the whole of it, and the arithmetic that decides is the conformance-tested code in the text assembly rather than a loop here that would get the interesting scripts wrong.

Fields and properties (36)

• protected override string TagName

  The element name this type answers to when a caller does not choose one.

• public string? Value
• public string? Placeholder
• public bool ReadOnly
• public int MaxLength
• public bool Required
• public Func<string?, string?>? Validator

  What decides whether the value is acceptable, for a caller that will not subclass.

• public string? ValidationMessage

  Why the value is not acceptable, or null when it is.

• public bool IsValid

  Whether the value is acceptable.

• public int CaretIndex

  Where the caret is, as a UTF-16 index into Value.

• public TimeSpan CaretBlink

  How long the caret spends on, and then off. Zero draws it solid.

• public CaretAffinity CaretAffinity

  Which of the two characters either side of CaretIndex the caret is on.

• public int SelectionAnchor

  Where the selection started, as a UTF-16 index. Equal to the caret when nothing is selected.

• public int SelectionStart

  The lower end of the selection.

• public int SelectionEnd

  The upper end.

• public bool HasSelection

  Whether anything is selected.

• public string SelectedText

  The selected text.

• public string Composition

  What an input method is composing at the caret, and has not committed.

• public bool IsComposing

  Whether an input method has an uncommitted pre-edit in this field.

• public int DisplayCaret

  Where the caret is in the string the field is displaying.

• protected UiElement TextPart

  The element the value is drawn on.

• protected override AccessibleRole NativeRole

  The role this kind of element has when nobody says otherwise.

• protected override string? NativeAccessibleName
• protected override string? NativeAccessibleValue
• protected override AccessibleStates NativeAccessibleState
• public bool CanCopy

  Whether there is something to put on the clipboard, and somewhere to put it.

• public bool CanPaste

  Whether there is text on the clipboard and this field would take it.

• protected virtual bool AcceptsNewlines

  Whether Enter puts a line break in the value rather than submitting it.

• protected bool ShowsCaret

  Whether the caret is drawn: a field that cannot be typed into has none.

• public Rectangle CaretArea
• public bool AcceptsTextInput
• public static readonly UiPropertyKey ValueProperty

  Identity for Value.

• public static readonly UiPropertyKey PlaceholderProperty

  Identity for Placeholder.

• public static readonly UiPropertyKey ReadOnlyProperty

  Identity for ReadOnly.

• public static readonly UiPropertyKey MaxLengthProperty

  Identity for MaxLength.

• public static readonly UiPropertyKey RequiredProperty

  Identity for Required.

Events (2)

• public Action<TextField, string?>? ValueChanged

  Raised after the value changes, whoever changed it.

• public Action<TextField>? Submitted

  Raised when Enter is pressed in the field.

Methods (23)

• protected override void OnCreated()

  Builds whatever this element is made of, once, as it joins a document.

• public void MoveCaret(int index, bool extend = false)

  Moves the caret, and either drops the selection or extends it.

• public void MoveCaret(int index, CaretAffinity affinity, bool extend = false)

  Moves the caret to one side of an index, and either drops the selection or extends it.

• public void SelectAll()

  Selects the whole value.

• public void SelectWord(int index)

  Selects the word an index falls inside.

• public void Replace(string insertion)

  Replaces the selection — or, with none, inserts at the caret.

• public bool Undo()

  Takes back the last edit, if this field is under an undo manager.

• public bool Redo()

  Puts back the last undone edit.

• public bool Copy()

  Puts the selection on the clipboard.

• public bool Cut()

  Puts the selection on the clipboard and deletes it.

• public bool Paste()

  Replaces the selection with the clipboard's text.

• protected virtual string? Coerce(string? value)

  What the field does with a value on its way in.

• protected virtual string? Shown(string? value)

  What the field draws for a value on its way out.

• protected virtual string? Validate(string? value)

  Whether a value is acceptable, and why not when it is not.

• public void Revalidate()

  Asks Validate again and republishes the answer.

• protected virtual void OnSubmit()

  Called when Enter is pressed, before Submitted is raised.

• protected virtual void SelectAt(int index, int count)

  What a repeated tap selects.

• protected override void OnDraw(DrawContext context)
• public void ClearValue()

  Unsets Value, so it takes its default or its ancestor's value again.

• public void ClearPlaceholder()

  Unsets Placeholder, so it takes its default or its ancestor's value again.

• public void ClearReadOnly()

  Unsets ReadOnly, so it takes its default or its ancestor's value again.

• public void ClearMaxLength()

  Unsets MaxLength, so it takes its default or its ancestor's value again.

• public void ClearRequired()

  Unsets Required, so it takes its default or its ancestor's value again.

Used by (130, showing 40)

• GalleryHelloUi
• AccessibilityTreeTestsVixen.Ui.Controls.Tests
• AccessibleNameLocalisationTestsVixen.Ui.Controls.Advanced.Tests
• BindReachTestsVixen.Ui.Controls.Tests
• CaretAffinityTestsVixen.Ui.Controls.Tests
• CaretBlinkTestsVixen.Ui.Controls.Tests
• CaretColourPixelTestsVixen.Ui.Controls.Tests
• ClipboardTestsVixen.Ui.Controls.Tests
• ColorPickerVixen.Ui.Controls.Advanced
• ColorPickerTestsVixen.Ui.Controls.Advanced.Tests
• ComboBoxVixen.Ui.Controls
• ComboEditorVixen.Ui.Controls
• CommandBindingTestsVixen.Ui.Controls.Tests
• ControlThemeVisualTestsVixen.Ui.Controls.Tests
• DataCellVixen.Ui.Controls.Advanced
• DataGridVixen.Ui.Controls.Advanced
• DataGridTestsVixen.Ui.Controls.Advanced.Tests
• DialogServiceVixen.Ui.Controls
• DialogTestsVixen.Ui.Controls.Tests
• DisabledStateTestsVixen.Ui.Controls.Tests
• DockingTestsVixen.Ui.Controls.Advanced.Tests
• EditingParityTestsVixen.Ui.Controls.Advanced.Tests
• ElementStateBitTestsVixen.Ui.Controls.Tests
• FieldProbeVixen.Ui.Controls.Tests
• FieldValidationTestsVixen.Ui.Controls.Tests
• MarkupTestsVixen.Ui.Controls.Tests
• NavigationInteractionTestsVixen.Ui.Controls.Tests
• NestedMemberTestsVixen.Ui.Controls.Advanced.Tests
• NodeCanvasVixen.Ui.Controls.Advanced
• NodePortEditorVixen.Ui.Controls.Advanced
• NumericInputVixen.Ui.Controls
• ProbeVixen.Ui.Desktop.Tests
• PropertyGridVixen.Ui.Controls.Advanced
• PropertyGridTestsVixen.Ui.Controls.Advanced.Tests
• RtlFieldMirroringTestsVixen.Ui.Controls.Tests
• ScrubTestsVixen.Ui.Controls.Tests
• SearchBoxVixen.Ui.Controls
• SearchableReachTestsVixen.Ui.Controls.Tests
• SearchableSheetVixen.Ui.Controls.Tests
• SecureTextBoxVixen.Ui.Controls